As is well known, in a mobile wireless terminal apparatus, it is important to reduce power consumption. A technique for reducing power consumption is also applied to a process of searching for a base station which is accommodated in a network. For example, when the mobile wireless terminal apparatus is outside the service area of the base station, if the base station cannot be detected for a long time, the cycle of search is made longer, thereby lowering the frequency of search and reducing power consumption.
In this conventional method, however, if the cycle of search becomes longer, a delay occurs in detecting that the mobile wireless terminal apparatus has moved into the service area or has moved out of the service area, resulting in degradation in convenience for users.